His visit reflects what must be deep disquiet in the government about the way things have gone – and not gone – on Manus Island, despite its refusal to acknowledge many of the obvious problems there.

But while there were some steps forward out of Morrison’s trip, there should also be questions and concerns about the two countries’ plan to “synthesise” the various inquiries into the recent rioting that saw one death and many serious injuries.

Let’s start with the positives, as reflected in Morrison’s statement on Sunday.

There is to be a new “monthly joint ministerial forum”, starting in April, “to directly oversee implementation of the regional resettlement arrangement”.

This forum will involve Foreign Minister Julie Bishop as well as Morrison.

“It will provide clear direction and oversight to the implementation of the RRA and provide a timely and accountable process to ensure that the arrangement is being converted into tangible and practical outcomes.” The recent “tragic incident” and the joint response will be an early focus “to ensure a co-ordinated and co-operative approach”.

Morrison said he and the PNG Minister for Foreign Affairs and Immigration, Rimbink Pato, and Attorney-General Kerenga Kua had agreed that central to the arrangement between the two countries “is the processing of asylum claims and the resettlement of genuine refugees in PNG”.

The forum “will enable progress on processing and resettlement arrangements to be reported on a monthly basis to ministers, to ensure that the momentum that is necessary to fulfil the objectives of the agreement is maintained”.

The first thing to say about this is that such co-ordination should have been set up long ago. And before Morrison uses as an excuse that he was left a blank sheet by the Rudd government, let us note that even accepting his point, he’s had months to do something about it.

Secondly, talk of “momentum” should be in the future tense. There has been none so far in terms of processing results.

Morrison said Australia and PNG “will work to synthesise, as appropriate” the inquiries each country has on the go into the rioting. These include the Australian investigation being done by Robert Cornall, a former secretary of the Attorney-General’s department, the PNG police investigation and the PNG coronial inquiry.

The aim is “to ensure a clear statement of the facts and a shared understanding of the findings and implications of these events for the ongoing management of the centre and the resettlement process”.

The ministers agreed the Cornall review “should be conducted in partnership and with the participation of the PNG government”.

At one level this seems sensible co-ordination.

But at another, it raises some worries. Isn’t it odd to have a coronial inquiry “synthesised” – a strange word in itself – with other investigations?

And once the Cornall inquiry is conducted “in partnership and with the participation of the PNG government”, surely there is a risk that the imperatives of diplomacy compromise its “independence”?

Meanwhile the Greens’ Sarah Hanson-Young is proposing a Senate inquiry into Manus and the recent incident in particular. But she needs Labor support; she will have talks with opposition spokesman Richard Marles on Monday. Labor, as the instigator of the “PNG solution”, is in an awkward position on the whole Manus issue.

Prime Minister Tony Abbott, pressed on whether he had had a “moment of doubt” about what Australia was doing, given the death of young Iranian Reza Barati and the injuries, told Ten Network on Sunday:

“Look, people should not engage in riotous affray. Now if they do engage in riotous affray, they’ve got to be dealt with humanely as well as sometimes firmly, but we are going to get to the bottom of this particular tragedy. Scott Morrison has been in PNG over the last 24 hours or so, amongst other things, to try to ensure that this happens.”

Let’s hope that in the end, we get the full truth, not a version varnished to preserve the niceties between the two countries in relation to a policy where Australia depends on PNG goodwill and PNG depends on Australian money.

Listen to the new Politics with Michelle Grattan podcast with Palmer United Party leader Clive Palmer here.